Orthopedic fastener blocking system

ABSTRACT

In an exemplary embodiment, the present invention provides an orthopedic fastener blocking system that allows for a desirable number of fasteners to be used with an orthopedic device even when the orthopedic device is too small to accommodate a desired number of traditionally located and oriented fasteners or when the accessibility to the device is reduced so that addressing a desired number of traditionally located and oriented fasteners is not possible. The system includes an orthopedic implant and at least first and second fasteners where one of the first and second fasteners prevents the other of the first and second fasteners from uninstalling when the first and second fasteners are in the installed position.

FIELD OF THE INVENTION

The present invention is generally directed to orthopedic fasteners usedto secure an orthopedic device to bone tissue. In particular, thepresent invention relates to a system of blocking the orthopedicfasteners to prevent the fasteners from disengaging or dislodging fromthe orthopedic implant.

BACKGROUND OF THE INVENTION

As is known in the field of orthopedic surgery, and more specificallyspinal surgery, orthopedic fasteners may be used for fixation or for theanchoring of orthopedic devices or implants to bone tissue. An exemplaryuse of orthopedic fasteners can include using the fasteners to fasten anorthopedic device or implant, such as a bone plate, a spinal rod, or aspinal spacer to a vertebral body for the treatment of a deformity ordefect in a patient's spine. Focusing on the bone plate example,orthopedic fasteners can be secured to a number of vertebral bodies anda bone plate can then be connected to the vertebral bodies via theorthopedic fasteners to fuse a segment of the spine. Turning to thespinal spacer example, orthopedic fasteners can be used to fix thelocation of a spinal spacer once the spacer is implanted betweenadjacent vertebral bodies. In each of the examples, orthopedic fastenersare used in conjunction with the orthopedic implant to treat theaffected area.

However, in some cases, where the size of the treatment area requires asmaller implant or the location of the area needed to be treateddictates reduced accessibility, the number and location of the fastenersmay be limited. With a reduced number of fasteners, it is possible thatthe orthopedic device can become dislodged or disconnected from the areaof treatment.

In addition, over time, it has been found that as a result of the forcesplaced upon the orthopedic device and fasteners resulting from themovement of the spine, the orthopedic fasteners can begin to “back out”from their installed position eventually resulting in the fastenersdisconnecting from the device.

As such, there exists a need for an orthopedic fastener blocking systemthat allows for a desirable number of fasteners to be used with anorthopedic device regardless of the device size and accessibility wherethe fasteners are blocked to prevent the fasteners from “backing out” oftheir installed position.

SUMMARY OF THE INVENTION

In one embodiment, the present invention provides an orthopedic fastenerblocking system that allows for a desirable number of fasteners to beused with an orthopedic device even when the orthopedic device is toosmall to accommodate a desired number of traditionally located andoriented fasteners or when the accessibility to the device is reduced sothat addressing a desired number of traditionally located and orientedfasteners is not possible. The system, in one embodiment, includes anorthopedic implant and at least first and second fasteners where one ofthe first and second fasteners prevents the other of the first andsecond fasteners from uninstalling when the first and second fastenersare in the installed position.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred or exemplary embodiments of the invention, areintended for purposes of illustration only and are not intended to limitthe scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a partial perspective view of one embodiment of an orthopedicfastener blocking system;

FIG. 2 is a schematic side view of another embodiment of an orthopedicfastener blocking system; and

FIG. 3 is schematic top view of the system shown in FIG. 2;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

With reference to FIG. 1, an embodiment of an orthopedic fastenerblocking system 10 is illustrated. Although the system 10 is shownisolated from the environment it would typically be used in, it shouldbe understood that the system 10 provides a fastening and fastenerblocking system that allows for a desirable number of fasteners to beused with an orthopedic device when the orthopedic device is too smallto accommodate a desired number of traditionally located and orientedfasteners or when the accessibility to the device is reduced so thataddressing a desired number of traditionally located and orientedfasteners is not possible.

The system 10 preferably includes an orthopedic device or implant 28; atleast a first fastener 12 having a head portion 14, a shank portion 16,and threads 18 that surround at least a portion of the shank portion 16;and a second fastener 20 having a head portion 22, a shank portion 24,and threads 26 that surround at least a portion of the shank portion 24.Although only two fasteners are shown, it is contemplated that thesystem 10 can include any number of fasteners. Further, the implant 28can be any one of a number of spinal implants including bone plates,spinal rods, and intervertebral spacers.

The system 10 can also include a blocking mechanism 34 which, in oneembodiment, is a set screw having an enlarged head portion 36. Althoughthe blocking mechanism 34 is identified as being a set screw, anymechanism that would serve as a blocking mechanism is contemplated, suchas a cam type mechanism or a slideable interference mechanism.Alternatively, a separate blocking mechanism may not be included at all,rather a channel in the implant 28 may be configured and dimensioned toallow a fastener to pass through in one direction put prevent thefastener from moving in the opposite direction.

With continued reference to the embodiment of the system 10 shown inFIG. 1, the implant 28 includes channels 30 and 32, the channels 30 and32 being configured and dimensioned to receive the fasteners 12 and 20.The channels 30 and 32 each have a separate and spaced opening and eachdefine a longitudinal axis, axis A and axis B, respectively. In oneembodiment, longitudinal axis A and longitudinal axis B intersect at anon-perpendicular, and preferably acute, angle. As further explainedbelow, this intersecting configuration allows for the blocking of onefastener by a second fastener and allows for the placement of thefasteners in closer proximity to each other. It should be noted thatalthough only two channels are discussed, it is contemplated that theimplant 28 can include any number of channels and each channel iscapable of receiving at least one fastener.

In an exemplary use of the system 10 as shown in FIG. 1, the implant 28is placed on or near the area of treatment. The fastener 12 is installedthrough channel 30 along axis A from a first uninstalled position to asecond installed position where the fastener 12, in the installedposition, engages the implant 28 as well as the anatomy in the area oftreatment to secure implant 28 in place. After the fastener 12 isinstalled in place, the fastener 20 is installed through channel 32along axis B from a first uninstalled position to a second installedposition. The orientation of channels 30 and 32 and axes A and B aresuch that when the fastener 20 is installed, it will intersect the pathof installation of fastener 12. Accordingly, the fastener 20, when inthe second installed position, engages the implant 28 and the anatomy ofthe area of treatment as well as blocks fastener 12 from “backing out”or from moving in an opposite direction from the direction ofinstallation. More specifically, the fastener 20 can be installed in anynumber of positions along axis B and any portion of fastener 20 can beused to block the fastener 12 including the head portion 22 or the shaftportion 24. Once the fastener 20 is installed in place, the blockingmechanism 34 is manipulated so that the enlarged head portion 36 blocksfastener 20 from “backing out” or from moving in an opposite directionfrom the direction of installation.

Turning to FIGS. 2 and 3, another embodiment of an orthopedic fastenerblocking system 100 is shown. The system 100 preferably includes atleast a first fastener 112, a second fastener 120, and an orthopedicimplant 128. Although only two fasteners are shown, it is contemplatedthat the system 100 can include any number of fasteners. Further, theimplant 128 can be any one of a number of spinal implants including boneplates, spinal rods, and intervertebral spacers.

The system 100 can also include a blocking mechanism 134. Alternatively,a separate blocking mechanism may not be included at all, rather achannel in the implant 128 may be configured and dimensioned to allow afastener to pass through in one direction put prevent the fastener frommoving in the opposite direction.

With continued reference to the embodiment of the system 100 shown inFIGS. 2 and 3, the implant 128 includes channels 130 and 132, thechannels 130 and 132 define a longitudinal axis, axis A and axis B,respectively, and are configured and dimensioned to receive thefasteners 112 and 120. In one embodiment, the openings of the channels130 and 132 each have intersecting openings and longitudinal axes A andB are generally parallel to each other. As further explained below, thischannel configuration allows for the blocking of one fastener by asecond fastener. It should be noted that although only two channels arediscussed, it is contemplated that the implant 128 can include anynumber of channels and each channel is capable of receiving at least onefastener.

In an exemplary use of the system 100 as shown in FIGS. 2 and 3, theimplant 128 is placed in the area of treatment. The fastener 112 isinstalled through channel 130 along axis A from a first uninstalledposition to a second installed position where the fastener 12, in theinstalled position, engages the implant 28 as well as the anatomy in thearea of treatment to secure implant 28 in place. After the fastener 112is installed in place, the fastener 120 is installed through channel 132along axis B from a first uninstalled position to a second installedposition. The intersection of channels 130 and 132 is such that when thefastener 120 is installed, it will intersect the path of installation offastener 112. Accordingly, the fastener 120, when in the secondinstalled position, engages the implant 128 and the anatomy of the areaof treatment as well as blocks fastener 112 from “backing out” or frommoving in an opposite direction from the direction of installation. Morespecifically, the fastener 120 can be installed in any number ofpositions along axis B and the head portion of the fastener 120 can beused to block the fastener 112. Once the fastener 120 is installed inplace, the blocking mechanism 134 is manipulated so that a portion ofthe blocking mechanism 134 blocks the fastener 120 from “backing out” orfrom moving in an opposite direction from the direction of installation.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

1. A fastening assembly for fastening an orthopedic implant to bonetissue, comprising: an orthopedic implant having at least a firstchannel and a second channel, the first channel defining a firstlongitudinal axis and the second channel defining a second longitudinalaxis; a first fastener, the first fastener capable of being received inthe first channel along the first longitudinal axis in a first directionfrom a first position to a second position; and a second fastener, thesecond fastener capable of being received in the second channel alongthe second longitudinal axis in a second direction from a first positionto a second position, wherein the second fastener prevents the firstfastener from moving in a direction opposite the first direction whenthe first fastener and the second fastener are in the second position.2. The assembly of claim 1, wherein the first longitudinal axisintersects the second longitudinal axis.
 3. The assembly of claim 2,wherein the angle of intersection is an acute angle.
 4. The assembly ofclaim 1, wherein the first longitudinal axis is generally parallel tothe second longitudinal axis.
 5. The assembly of claim 1, wherein theopening of the first channel is separate and distinct from the openingof the second channel.
 6. The assembly of claim 1, wherein the openingof the first channel intersects with the opening of the second channel.7. The assembly of claim 1, further comprising a blocking mechanism forblocking the second fastener from moving in a direction opposite thefirst direction.
 8. The assembly of claim 1, wherein the second fastenerblocks the first fastener from moving in a direction opposite the firstdirection.
 9. The assembly of claim 8, wherein the head portion of thesecond fastener blocks the first fastener from moving in a directionopposite the first direction.
 10. The assembly of claim 8, wherein theshaft portion of the second fastener blocks the first fastener frommoving in a direction opposite the first direction.
 11. A method forfastening an orthopedic implant to anatomy in a treatment area,comprising: placing an orthopedic implant having a blocking mechanismand at least a first channel and a second channel, the first channeldefining a first longitudinal axis and the second channel defining asecond longitudinal axis proximate to the area of treatment; installinga first fastener through the first channel along the first longitudinalaxis in a first direction from a first position to a second positionwhere the first fastener engages the implant and the anatomy in the areaof treatment in the second position; and installing a second fastenerthrough the second channel along the second longitudinal axis in asecond direction from a first position to a second position where thesecond fastener engages the implant and the anatomy in the area oftreatment in the second position and where the second fastener blocksthe first fastener from moving in a direction opposite the firstdirection when the first fastener and the second fastener are in thesecond position.
 12. The method of claim 11, further comprisingmanipulating the blocking mechanism to block the second fastener frommoving in a direction opposite the first direction when the secondfastener is in the second position.